Electric phonograph



May 29, 1928. 1,6i1,509

G.B. BURCH ELECTRI C PHONOGRAPH Original Filed Ma. rch 8. 1918 2 Sheets-Sheet l May 29, 1928. 1,671,509

G. B. BURCH v ELECTRIC PHONOGRAPH Original Filed March 8. 191 8 2 Sheets-Shee't 2 INVENTOR ATTOR Y Patented May 29, 1928.

UNITED STATES GEORGE B. BURCH, OF NEW YORK, N. Y.,

ASSIGNOR T LESLIE STEVENS, 0F GLEN RIDGE, NEW JERSEY.

ELECTRIC PHONOGRAPH.

Application filed. March 8, 1918, Serial 110.221.5288. Renewed February 29,1924.

Fig. 2 is a diagrammatic view of the electrlc circuits in one form of apparatus with parts shown in series. I

Fig. 3 1s a view 1n accordance wlth Flg. 2 and much the same, except that the parts are shown in multiple.

Fig. 4 is a sectional view of an incomplete diaphragm.

Fig. 5 is a sectional view showing a diaphragm mounted to produce sound waves at a point remote from the record.

Throughout the various views of the drawings, similar reference characters designate similar parts.

My improved phonograph 1 is provided with any suitable casing 2 in which is mounted a motor 3, in the conventional manner and of any desired form, and from this motor extends the usual vertical shaft 4 on which is mounted a turntable of the conventional kind which carries. a, record 6, of the usual form. This-record may be of any kind, and it is immaterial whether this record has a groove irregular as to depth or irregular 'as to its side walls as the instrument works with equal fac'ility with either kind of record.

At one side of the turntable 5 and mounted on the casing 2 is a suitable bracket 7 which carries a-ve rtically disposed spindle 8 which is free to're volve about its axis and at the topof this spindle is placed a suitable nine inches to a foot in diameter has been found most desirable. The diaphragm 'is. of eonoidal form continuously curved from the center of the diaphragm outward in all radial directions. ,Therings 10 also have secured suitable washers 12 and arms 13 mounted on screws 14 which hold the parts together, and the arms 13 run to a. spiderbar has a needle holder 18 in which is mounted asuitable needle 19that is adapted to engage the groove in the record 6 in the conventional manner. The needle bar 17 is mounted near its lower end witha u-niversal joint, not shown, which permits a' limited universal movement, and at its upper "end it is fixed at the center of a small .metallic diaphragm 20 which isfixed to a'" bracket 21, that is in turn fixed to the tube 16 in any desired manner. Thediaphragm 20 carries an insulating ring .22 on which is a suitablemetallic box 23 which contains carbon 24 between it and the diaphragm 20 so as to form asuitable transmitter. The bracket 21 is extended to support electromagnets 25 which are held adjacent to an iron plate 26 which is securely fixed at the top-center of the convex or dished diaphragm 1]. which has been mentioned above. In the preferred embodiment of mymvention this diaphragm 11 is made of several thicknesses of sheet material, as paper or Bristol board, and has more layers at the center than at the circumference and has only-one layer at the circumferencewith the other layers terminating nearer the center. Sound vibrations generated in the metal diaphragm 26 are transmitted= directly to the amplifying diaphragm 11 which is thus set in vibration, andthese sound vibrations .are communicated to the atmosphere from the large surface of the diaphragm. The flexible formation of the gutter 27 permits the necessary vibratory movements of the dia-' phragm, even when its supporting members such as the rings 10 are heavy or rigid. Beyond the gutter 27 the diaphragm 11 is provided with a flat flange which is sandwiched in between the two rings 10, as shown. v a i Fig. 4 is an enlarged section of the diaphragm 11 before it has been provided with its metallic plate or diaphragm26 and show ing its form and laminated structure more clearly. i

The electric diagrams in Figs. 2 and 3 show accurately two systems of wiring,

7 either of which may be employed. In Fig. 2

the-diaphragm 20 of the transmitter is provided with a wire 28 thatruns to a battery 29 which in turn is connected toanother wire 30 that runs to the magnets 25 under the plate 26, and from thence a wire 31 runs to a box 23 on the insulation 22 so that when the. diaphragm 20 is vibrated, a circuit is modified by the action of the carbon 24 in the box 23, as is usual with'telephone trans- 'mitters, and the electric waves thus formed pass through the magnets 25 which with the plate 26 constitute a telephone receiver and.

these waves are amplified not by a horn or similar device but by the diaphragm 11 which is fixedto the diaphragm 26.

In the structure shown in Fig. 3 the wiring is much the same as before, the diaphragm 20 being connected with the battery 29 by a wire 28 and the wire 30 runs directly to the box 23 on the insulation 22, in the manner shown. 7 The magnets 25 are connected in parallel between the wires 28 and 30 by means of the wires 32 and 33 in the manner indicated. Here sound waves are modified the same as before at the transmitter and received in their modified form-at the receiver where the plate 26 is caused to vibrate accordingly, which vibrations are transmitted to the amplifying diaphragm 11 and transformed into sound waves which actually reproduce the sounds recorded in i the record 6. It is a feature of the apparacured to a box 34, orotherdevice of any desired form, and inthis box, and at centhe objecter, is mounted a support 35 of any conven- .ient kind, which carries the magnets 25,

which, in this embodiment of my invention, 7

are mounted on the convex side of the diaphragm 11 instead of the concave side as shown in Fig. 1. Wires 32 and '33 run to this instrument just as indicated in Fig. 3, and as many of these instruments may be connected in parallel as desired, or if the operator so wishes, they may all be connect? ed by wires so -as tobe in series. In any event, it is possible to havemultiple reproduction of the sound waves generated as above described, from a single transmitter. This may be of particular use where a large volume of sound is required,'as in; a ball room, auditorium or other place.

While I have shown and described one embodiment of my invention,.it is obvious that it is not restricted thereto but is broad enough to cover all structures that come within the scope of the annexed claims.

What I claim is:

gutter near its periphery with a magnetic metal fixed to said diaphragm at its center andadapted to receive magnetic waves and transform them into sound waves which are transmitted through the diaphragm.

2. In a device of the class described, apair of rings secured together with a diaphragm held between them, a spider connected to' saidrings andfa transmitterand a magnet operated thereby carried by-saidspider so that said magnet'will beadjacent to the diaphragm.

3. In a device-of the class described, two rings with a diaphragm held between them, a spider secured to said rings, a tube in said spider, a needle bar mounted in said tube, a transmitter fixed to said needle bar and sup- 1. A diaphragm of non magnetic material of dished form havinga reversely curved.

ported by a bracket connected to said tube, a

magnet adjacent to' the center of said diaphragm and adapted to causevibrations in the same, andmeans for causing the needle bar to transmit sound vibrations to the transmitter.

GEORGE B. BURCH. 

